Chlorphentermine (Apsedon, Desopimon, Lucofen) is a stimulant drug which was used as an appetite suppressant. It was invented in 1962, and is the 4-chloro derivative of the better known appetite suppressant phentermine,[1] which is still in current use.

Chlorphentermine itself is a relatively weak stimulant with little abuse potential, but is classed as a Schedule 3 drug in the USA due mainly to its similarity to other appetite suppressants such as diethylpropion which have been more widely abused. It is no longer used due mainly to safety concerns, as it has a serotonergic effects profile similar to other withdrawn appetite suppressants such as fenfluramine and aminorex which were found to cause pulmonary hypertension and cardiac fibrosis following prolonged use.[2]